To obtain the photosensitive composition capable of judging a proper exposure and setting exact exposure and the photosensitive material using this composition by incorporating a quinonediazide compound and an alkali- soluble resin and specified photodecolorizable dye.

This photosensitive composition contains at least the quinonediazide compound and the alkali-soluble reins and the photodecolorizable dye represented by the formula in which each of Z1-Z3 is a C or N atom; each of R1-R3 is an H atom or a substituent; and X+ is an organic cation. The photodecolorizable dye like this is preferable for this positive photosensitive material. This dye has a high light-absorbance and therefore, density difference due to exposure degree is high, namely, this dye is high in visual discriminability of the density difference after exposure and since the image visualized by exposure in preferable, it can be used for the positive photosensitive composition and the lithographic printing plate by using this composition, and photoresist.